TPMS stands for Tire Pressure Monitoring System. It is the federally mandated dashboard warning that alerts you when a tire is more than 25% below the recommended pressure. Required on every passenger vehicle sold in the US since September 2007.
Each wheel has a battery-powered sensor measuring actual pressure. Used by most cars. Sensors last 5-10 years.
No sensors. The car compares how fast each wheel turns. A low tire rotates slightly faster. Used by some Hondas, Mazdas. No sensor replacement ever.
TPMS lights up at about 25% below the door jamb PSI. If placard is 35, light comes on around 26 PSI.
Solid light: tire is low - check pressures. Flashing then solid (60-90 sec at startup): sensor fault - get it scanned.
Federal law since September 2007 due to Firestone-Ford rollover deaths. Any car newer than 2007 has TPMS. Cannot legally remove or disable it in inspection states.
| What You See | What It Means |
|---|---|
| Solid amber/yellow light | One or more tires at least 25% low |
| Flashing 60-90 sec then solid | Sensor system fault - get scanned |
| Light comes on in cold weather | Temperature dropped pressure - top off |
| Light on with low warning chime | Severely low - check immediately |
| Light stays on after filling | Needs relearn drive or button reset |
Tell us solid or flashing, when it came on, and your car details - we'll tell you what to do.
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Tire Pressure Monitoring System - the federally mandated warning system that alerts you when a tire is at least 25% below recommended pressure. Required on US passenger vehicles since September 2007.
Direct TPMS uses a battery-powered sensor inside each wheel that radios pressure to the car. Indirect TPMS uses wheel-speed sensors (ABS) to detect when one tire is rotating slightly faster than others (because it is low).
Direct TPMS is accurate within 1-2 PSI. Indirect TPMS can be off by more and depends on calibration. Either way: always verify with a manual gauge.
Tire pressure drops about 1 PSI for every 10F drop in temperature. If you set 35 PSI in summer (80F) and it drops to 20F, you have lost 6 PSI - enough to trigger the warning. Top off all four.
5-10 years on average. Each sensor has a sealed lithium battery that cannot be replaced separately. Once dead, the whole sensor goes for $40-$80 plus install.
Not legally. Some aftermarket products claim to disable it but state inspections will fail. Also: TPMS saves lives - the data on tire-related crashes since 2007 supports keeping it on.